Can somebody give me some advice,I feel very helpless?

Tommorow is Father Day I think,and this morning I found out that a friend of mines dad passed away in the early hours of this morning. (Its just awful because his dad was quiet young,and the disease he had unfortunately got was only properly diagnosed about three weeks ago). The friend is one of my best friends boyfriends,so that's how I know him,know him for around three years. He is one of the best people I know,and while I know that this whole situation is most definatly not about me,it deeply pisses me off that these kind of things happen to very good people. Obviously this friend is in a bad place at the moment,and I won't give him a shout or anything today,just let him be with his family and cousins and grieve without hassle from outsiders. I only ever saw his Dad twice I think,or heard him on the phone to my friend. Anyway,I guess what I'm asking for is,(I have no clue what to do) how should I be there for this friend. Obviously I will go to the funeral and pay my respects,but I feel very awkward at funerals (who doesn't),I know that sounds extremely petty,but I really have no clue when it comes to these things. The only time I ever knew someone close who passed away was a close friend of mine in my childhood. I know that my close friend who is his girlfriend will be there for him, (shes been great in throughout this whole sadness,shes definatly been his rock),and that he will know that he is not alone,but I guess I don't know what to say to the lad. Words like 'sorry for your loss' seem so..blank. Do I just say a hello and act like myself? God I'm such a toolbag,I can't believe I'm even posting this. Any advice (please be sincere) would be greatly appreciated. Thanks.